The present invention relates to a method for degreasing a cold rolled metallic band, and more particularly a band treated continuously, preferably a ferrous band, or a copper band.
This invention is an improvement to that disclosed and claimed in USA patent application No. 389,153 dated June 16, 1983, now abandoned, by the present applicant. In this prior patent application is disclosed a degreasing method of a cold rolled metallic band in which the heating and degreasing actions are separated:
(a) the heating is carried out in an enclosure provided with means for bringing heat by radiation, notably electrical; and
(b) the degreasing is obtained through the effect of an appropriate atmosphere in the heating enclosure.
In this prior patent application, the atmosphere used is made of a mixture of N.sub.2, H.sub.2, H.sub.2 O, CO.sub.2 and CO, and it results from the sub-stoichiometric combustion of a fossil fuel (gas or oil). The total degreasing of the metallic band is therefore obtained by the heating and cracking of the oils, by the chemical action of the gases of the atmosphere of the fumes resulting from the combustion of said fossil fuel.
Therefore, the atmosphere having the aforementioned composition in the prior patent application includes reducing gases (H.sub.2 and CO), and also oxidizing gases (H.sub.2 O and CO.sub.2).